/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Scatterlist Cryptographic API. * * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> * Copyright (c) 2002 David S. Miller (davem@redhat.com) * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au> * * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no> * and Nettle, by Niels Möller. */ #ifndef _LINUX_CRYPTO_H #define _LINUX_CRYPTO_H #include <linux/completion.h> #include <linux/errno.h> #include <linux/refcount_types.h> #include <linux/slab.h> #include <linux/types.h> /* * Algorithm masks and types. */ #define CRYPTO_ALG_TYPE_MASK 0x0000000f #define CRYPTO_ALG_TYPE_CIPHER 0x00000001 #define CRYPTO_ALG_TYPE_AEAD 0x00000003 #define CRYPTO_ALG_TYPE_LSKCIPHER 0x00000004 #define CRYPTO_ALG_TYPE_SKCIPHER 0x00000005 #define CRYPTO_ALG_TYPE_AKCIPHER 0x00000006 #define CRYPTO_ALG_TYPE_SIG 0x00000007 #define CRYPTO_ALG_TYPE_KPP 0x00000008 #define CRYPTO_ALG_TYPE_ACOMPRESS 0x0000000a #define CRYPTO_ALG_TYPE_SCOMPRESS 0x0000000b #define CRYPTO_ALG_TYPE_RNG 0x0000000c #define CRYPTO_ALG_TYPE_HASH 0x0000000e #define CRYPTO_ALG_TYPE_SHASH 0x0000000e #define CRYPTO_ALG_TYPE_AHASH 0x0000000f #define CRYPTO_ALG_TYPE_ACOMPRESS_MASK 0x0000000e #define CRYPTO_ALG_LARVAL 0x00000010 #define CRYPTO_ALG_DEAD 0x00000020 #define CRYPTO_ALG_DYING 0x00000040 #define CRYPTO_ALG_ASYNC 0x00000080 /* * Set if the algorithm (or an algorithm which it uses) requires another * algorithm of the same type to handle corner cases. */ #define CRYPTO_ALG_NEED_FALLBACK 0x00000100 /* * Set if the algorithm data structure should be duplicated into * kmalloc memory before registration. This is useful for hardware * that can be disconnected at will. Do not use this if the data * structure is embedded into a bigger one. Duplicate the overall * data structure in the driver in that case. */ #define CRYPTO_ALG_DUP_FIRST 0x00000200 /* * Set if the algorithm has passed automated run-time testing. Note that * if there is no run-time testing for a given algorithm it is considered * to have passed. */ #define CRYPTO_ALG_TESTED 0x00000400 /* * Set if the algorithm is an instance that is built from templates. */ #define CRYPTO_ALG_INSTANCE 0x00000800 /* Set this bit if the algorithm provided is hardware accelerated but * not available to userspace via instruction set or so. */ #define CRYPTO_ALG_KERN_DRIVER_ONLY 0x00001000 /* * Mark a cipher as a service implementation only usable by another * cipher and never by a normal user of the kernel crypto API */ #define CRYPTO_ALG_INTERNAL 0x00002000 /* * Set if the algorithm has a ->setkey() method but can be used without * calling it first, i.e. there is a default key. */ #define CRYPTO_ALG_OPTIONAL_KEY 0x00004000 /* * Don't trigger module loading */ #define CRYPTO_NOLOAD 0x00008000 /* * The algorithm may allocate memory during request processing, i.e. during * encryption, decryption, or hashing. Users can request an algorithm with this * flag unset if they can't handle memory allocation failures. * * This flag is currently only implemented for algorithms of type "skcipher", * "aead", "ahash", "shash", and "cipher". Algorithms of other types might not * have this flag set even if they allocate memory. * * In some edge cases, algorithms can allocate memory regardless of this flag. * To avoid these cases, users must obey the following usage constraints: * skcipher: * - The IV buffer and all scatterlist elements must be aligned to the * algorithm's alignmask. * - If the data were to be divided into chunks of size * crypto_skcipher_walksize() (with any remainder going at the end), no * chunk can cross a page boundary or a scatterlist element boundary. * aead: * - The IV buffer and all scatterlist elements must be aligned to the * algorithm's alignmask. * - The first scatterlist element must contain all the associated data, * and its pages must be !PageHighMem. * - If the plaintext/ciphertext were to be divided into chunks of size * crypto_aead_walksize() (with the remainder going at the end), no chunk * can cross a page boundary or a scatterlist element boundary. * ahash: * - crypto_ahash_finup() must not be used unless the algorithm implements * ->finup() natively. */ #define CRYPTO_ALG_ALLOCATES_MEMORY 0x00010000 /* * Mark an algorithm as a service implementation only usable by a * template and never by a normal user of the kernel crypto API. * This is intended to be used by algorithms that are themselves * not FIPS-approved but may instead be used to implement parts of * a FIPS-approved algorithm (e.g., dh vs. ffdhe2048(dh)). */ #define CRYPTO_ALG_FIPS_INTERNAL 0x00020000 /* Set if the algorithm supports virtual addresses. */ #define CRYPTO_ALG_REQ_VIRT 0x00040000 /* Set if the algorithm cannot have a fallback (e.g., phmac). */ #define CRYPTO_ALG_NO_FALLBACK 0x00080000 /* The high bits 0xff000000 are reserved for type-specific flags. */ /* * Transform masks and values (for crt_flags). */ #define CRYPTO_TFM_NEED_KEY 0x00000001 #define CRYPTO_TFM_REQ_MASK 0x000fff00 #define CRYPTO_TFM_REQ_FORBID_WEAK_KEYS 0x00000100 #define CRYPTO_TFM_REQ_MAY_SLEEP 0x00000200 #define CRYPTO_TFM_REQ_MAY_BACKLOG 0x00000400 #define CRYPTO_TFM_REQ_ON_STACK 0x00000800 /* * Miscellaneous stuff. */ #define CRYPTO_MAX_ALG_NAME 128 /* * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual * declaration) is used to ensure that the crypto_tfm context structure is * aligned correctly for the given architecture so that there are no alignment * faults for C data types. On architectures that support non-cache coherent * DMA, such as ARM or arm64, it also takes into account the minimal alignment * that is required to ensure that the context struct member does not share any * cachelines with the rest of the struct. This is needed to ensure that cache * maintenance for non-coherent DMA (cache invalidation in particular) does not * affect data that may be accessed by the CPU concurrently. */ #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN))) struct crypto_tfm; struct crypto_type; struct module; typedef void (*crypto_completion_t)(void *req, int err); /** * DOC: Block Cipher Context Data Structures * * These data structures define the operating context for each block cipher * type. */ struct crypto_async_request { struct list_head list; crypto_completion_t complete; void *data; struct crypto_tfm *tfm; u32 flags; }; /** * DOC: Block Cipher Algorithm Definitions * * These data structures define modular crypto algorithm implementations, * managed via crypto_register_alg() and crypto_unregister_alg(). */ /** * struct cipher_alg - single-block symmetric ciphers definition * @cia_min_keysize: Minimum key size supported by the transformation. This is * the smallest key length supported by this transformation * algorithm. This must be set to one of the pre-defined * values as this is not hardware specific. Possible values * for this field can be found via git grep "_MIN_KEY_SIZE" * include/crypto/ * @cia_max_keysize: Maximum key size supported by the transformation. This is * the largest key length supported by this transformation * algorithm. This must be set to one of the pre-defined values * as this is not hardware specific. Possible values for this * field can be found via git grep "_MAX_KEY_SIZE" * include/crypto/ * @cia_setkey: Set key for the transformation. This function is used to either * program a supplied key into the hardware or store the key in the * transformation context for programming it later. Note that this * function does modify the transformation context. This function * can be called multiple times during the existence of the * transformation object, so one must make sure the key is properly * reprogrammed into the hardware. This function is also * responsible for checking the key length for validity. * @cia_encrypt: Encrypt a single block. This function is used to encrypt a * single block of data, which must be @cra_blocksize big. This * always operates on a full @cra_blocksize and it is not possible * to encrypt a block of smaller size. The supplied buffers must * therefore also be at least of @cra_blocksize size. Both the * input and output buffers are always aligned to @cra_alignmask. * In case either of the input or output buffer supplied by user * of the crypto API is not aligned to @cra_alignmask, the crypto * API will re-align the buffers. The re-alignment means that a * new buffer will be allocated, the data will be copied into the * new buffer, then the processing will happen on the new buffer, * then the data will be copied back into the original buffer and * finally the new buffer will be freed. In case a software * fallback was put in place in the @cra_init call, this function * might need to use the fallback if the algorithm doesn't support * all of the key sizes. In case the key was stored in * transformation context, the key might need to be re-programmed * into the hardware in this function. This function shall not * modify the transformation context, as this function may be * called in parallel with the same transformation object. * @cia_decrypt: Decrypt a single block. This is a reverse counterpart to * @cia_encrypt, and the conditions are exactly the same. * * All fields are mandatory and must be filled. */ struct cipher_alg { unsigned int cia_min_keysize; unsigned int cia_max_keysize; int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen); void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src); void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src); }; #define cra_cipher cra_u.cipher /** * struct crypto_alg - definition of a cryptograpic cipher algorithm * @cra_flags: Flags describing this transformation. See include/linux/crypto.h * CRYPTO_ALG_* flags for the flags which go in here. Those are * used for fine-tuning the description of the transformation * algorithm. * @cra_blocksize: Minimum block size of this transformation. The size in bytes * of the smallest possible unit which can be transformed with * this algorithm. The users must respect this value. * In case of HASH transformation, it is possible for a smaller * block than @cra_blocksize to be passed to the crypto API for * transformation, in case of any other transformation type, an * error will be returned upon any attempt to transform smaller * than @cra_blocksize chunks. * @cra_ctxsize: Size of the operational context of the transformation. This * value informs the kernel crypto API about the memory size * needed to be allocated for the transformation context. * @cra_alignmask: For cipher, skcipher, lskcipher, and aead algorithms this is * 1 less than the alignment, in bytes, that the algorithm * implementation requires for input and output buffers. When * the crypto API is invoked with buffers that are not aligned * to this alignment, the crypto API automatically utilizes * appropriately aligned temporary buffers to comply with what * the algorithm needs. (For scatterlists this happens only if * the algorithm uses the skcipher_walk helper functions.) This * misalignment handling carries a performance penalty, so it is * preferred that algorithms do not set a nonzero alignmask. * Also, crypto API users may wish to allocate buffers aligned * to the alignmask of the algorithm being used, in order to * avoid the API having to realign them. Note: the alignmask is * not supported for hash algorithms and is always 0 for them. * @cra_reqsize: Size of the request context for this algorithm. * @cra_priority: Priority of this transformation implementation. In case * multiple transformations with same @cra_name are available to * the Crypto API, the kernel will use the one with highest * @cra_priority. * @cra_name: Generic name (usable by multiple implementations) of the * transformation algorithm. This is the name of the transformation * itself. This field is used by the kernel when looking up the * providers of particular transformation. * @cra_driver_name: Unique name of the transformation provider. This is the * name of the provider of the transformation. This can be any * arbitrary value, but in the usual case, this contains the * name of the chip or provider and the name of the * transformation algorithm. * @cra_type: Type of the cryptographic transformation. This is a pointer to * struct crypto_type, which implements callbacks common for all * transformation types. There are multiple options, such as * &crypto_skcipher_type, &crypto_ahash_type, &crypto_rng_type. * This field might be empty. In that case, there are no common * callbacks. This is the case for: cipher. * @cra_u: Callbacks implementing the transformation. This is a union of * multiple structures. Depending on the type of transformation selected * by @cra_type and @cra_flags above, the associated structure must be * filled with callbacks. This field might be empty. This is the case * for ahash, shash. * @cra_init: Deprecated, do not use. * @cra_exit: Deprecated, do not use. * @cra_u.cipher: Union member which contains a single-block symmetric cipher * definition. See @struct @cipher_alg. * @cra_module: Owner of this transformation implementation. Set to THIS_MODULE * @cra_list: internally used * @cra_users: internally used * @cra_refcnt: internally used * @cra_destroy: internally used * * The struct crypto_alg describes a generic Crypto API algorithm and is common * for all of the transformations. Any variable not documented here shall not * be used by a cipher implementation as it is internal to the Crypto API. */ struct crypto_alg { struct list_head cra_list; struct list_head cra_users; u32 cra_flags; unsigned int cra_blocksize; unsigned int cra_ctxsize; unsigned int cra_alignmask; unsigned int cra_reqsize; int cra_priority; refcount_t cra_refcnt; char cra_name[CRYPTO_MAX_ALG_NAME]; char cra_driver_name[CRYPTO_MAX_ALG_NAME]; const struct crypto_type *cra_type; union { struct cipher_alg cipher; } cra_u; int (*cra_init)(struct crypto_tfm *tfm); void (*cra_exit)(struct crypto_tfm *tfm); void (*cra_destroy)(struct crypto_alg *alg); struct module *cra_module; } CRYPTO_MINALIGN_ATTR; /* * A helper struct for waiting for completion of async crypto ops */ struct crypto_wait { struct completion completion; int err; }; /* * Macro for declaring a crypto op async wait object on stack */ #define DECLARE_CRYPTO_WAIT(_wait) \ struct crypto_wait _wait = { \ COMPLETION_INITIALIZER_ONSTACK((_wait).completion), 0 } /* * Async ops completion helper functioons */ void crypto_req_done(void *req, int err); static inline int crypto_wait_req(int err, struct crypto_wait *wait) { switch (err) { case -EINPROGRESS: case -EBUSY: wait_for_completion(&wait->completion); reinit_completion(&wait->completion); err = wait->err; break; } return err; } static inline void crypto_init_wait(struct crypto_wait *wait) { init_completion(&wait->completion); } /* * Algorithm query interface. */ int crypto_has_alg(const char *name, u32 type, u32 mask); /* * Transforms: user-instantiated objects which encapsulate algorithms * and core processing logic. Managed via crypto_alloc_*() and * crypto_free_*(), as well as the various helpers below. */ struct crypto_tfm { refcount_t refcnt; u32 crt_flags; int node; struct crypto_tfm *fb; void (*exit)(struct crypto_tfm *tfm); struct crypto_alg *__crt_alg; void *__crt_ctx[] CRYPTO_MINALIGN_ATTR; }; /* * Transform user interface. */ struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask); void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm); static inline void crypto_free_tfm(struct crypto_tfm *tfm) { return crypto_destroy_tfm(tfm, tfm); } /* * Transform helpers which query the underlying algorithm. */ static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm) { return tfm->__crt_alg->cra_name; } static inline const char *crypto_tfm_alg_driver_name(struct crypto_tfm *tfm) { return tfm->__crt_alg->cra_driver_name; } static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm) { return tfm->__crt_alg->cra_blocksize; } static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm) { return tfm->__crt_alg->cra_alignmask; } static inline unsigned int crypto_tfm_alg_reqsize(struct crypto_tfm *tfm) { return tfm->__crt_alg->cra_reqsize; } static inline u32 crypto_tfm_get_flags(struct crypto_tfm *tfm) { return tfm->crt_flags; } static inline void crypto_tfm_set_flags(struct crypto_tfm *tfm, u32 flags) { tfm->crt_flags |= flags; } static inline void crypto_tfm_clear_flags(struct crypto_tfm *tfm, u32 flags) { tfm->crt_flags &= ~flags; } static inline unsigned int crypto_tfm_ctx_alignment(void) { struct crypto_tfm *tfm; return __alignof__(tfm->__crt_ctx); } static inline bool crypto_tfm_is_async(struct crypto_tfm *tfm) { return tfm->__crt_alg->cra_flags & CRYPTO_ALG_ASYNC; } static inline bool crypto_req_on_stack(struct crypto_async_request *req) { return req->flags & CRYPTO_TFM_REQ_ON_STACK; } static inline void crypto_request_set_callback( struct crypto_async_request *req, u32 flags, crypto_completion_t compl, void *data) { u32 keep = CRYPTO_TFM_REQ_ON_STACK; req->complete = compl; req->data = data; req->flags &= keep; req->flags |= flags & ~keep; } static inline void crypto_request_set_tfm(struct crypto_async_request *req, struct crypto_tfm *tfm) { req->tfm = tfm; req->flags &= ~CRYPTO_TFM_REQ_ON_STACK; } struct crypto_async_request *crypto_request_clone( struct crypto_async_request *req, size_t total, gfp_t gfp); static inline void crypto_stack_request_init(struct crypto_async_request *req, struct crypto_tfm *tfm) { req->flags = 0; crypto_request_set_tfm(req, tfm); req->flags |= CRYPTO_TFM_REQ_ON_STACK; } #endif /* _LINUX_CRYPTO_H */
